Solitary tumors of the peripheral nerves are uncommon and found to be benign in 90 p. 100 of the cases. They develop from the elements constituting the nerve and are generally schwannomas (80 p. 100). Other tumors are much more exceptional and exhibit wide histological variability.

The diagnosis of a tumor of the peripheral nerve must be envisaged for all cases with tumefaction or pain on the path of a nerve exacerbated at percussion. Magnetic resonance imaging is the preferred exploration technique, particularly useful in case of a deep tumor.

Preservation of nerve continuity is the underlying goal of the therapeutic strategy, irrespective of the type of tumor. Extricable tumors are to be distinguished from inextricable tumors. Extricable tumors (schwannomas, intranervous lipomas) displace nerve fiber bundles without penetrating into the bundle itself and can thus be resected without interrupting nerve continuity. Prognosis is excellent if no recurrence or degeneration occurs. In case of persistent symptoms, a new exploration may be required to search for other localized tumor(s) unperceived at the first procedure. Inextricable tumors (solitary neurofibromas, hemangiomas of the Schwann sheath, neurofibrolipomas) infiltrate the structural elements of the nerve fibers making complete excision impossible without altering the nerve fibers. Epineurotomy (associated with an interfascicular biopsy for pathology examination) allows decompression and can often provide symptom relief although moderate paresthesia may persist. Patients must be informed of this possibility prior to surgery. Any recent and rapidly evolving modification in the clinical findings is suggestive of recurrence and should be followed by revision exploration. Malignant degeneration has not been observed in solitary tumors to our knowledge. Our own experience with 51 cases is generally in agreement with reports in the literature.

Purpose: Desmoid tumours are uncommon in the axillary region. We report the clinical course in seven patients operated for desmoid tumours of the axillary region.

Material and methods: Our series included two women and five men. Mean age was 52 years (39–60). One tumour was in the trapesium, two were in the retroplexic, two in the axillary fossa, one in the deltoid and one in the upper part of the arm. Biopsy and magnetic resonance imaging were obtained in all patients. Surgical margins were in healthy tissue in five cases; resection was limited to intratumoural tissue in one. The axillary nerve had to be sacrificed in two patients, the spinal nerve in one and the medial nerve in one. Chemotherapy was given to one patient prior to surgery.

Results: Mean follow-up was 51 months (23.2–162.1). Five patients experienced at least one relapse requiring one or two complementary procedures. Among the relapse cases, one patient required resection of the median nerve with bypass of the humeral artery. No amputations were necessary and the brachial plexus was not sacrificed. Four patients were given one to five adjuvant chemotherapy courses. Two were given radiotherapy. Shoulder motion was preserved in two patients, moderately reduced in five. Elbow and finger mobility was compromised due to the medial epicondylar site of the tumour in one patient whose median nerve had to be sacrificed.

Discussion: Even though the surgical margins were in healthy tissue, the risk of relapse was high in our patients as in other series reported in the literature. The course does however stabilise after several episodes of recurrence, an observation reported in the literature and confirmed in our patients. In case of brachial plexus involvement, several authors advocate preservation of upper limb function despite incomplete tumour resection, proposing postoperative radiotherapy.

Conclusion: Desmoid tumours of the axillary region seriously compromise upper limb function. Surgical resection should be as complete as possible but without sacrificing upper limb function.

A mucoid pseudocyst of a peripheral nerve is a rare and benign tumour of controversial origin. We have reviewed ten patients with a mean follow-up of 3.2 years. The tumour affected the common peroneal nerve in eight and the ulnar nerve in two. The mean time between the onset of symptoms and diagnosis was 7.4 months (1.2 months to 2 years). On examination, there was pain in eight patients and swelling in seven. Motor deficit in the corresponding nerve territory was found in all. The diagnosis was usually confirmed by MRI. Treatment was always surgical.

All the patients recovered, with a mean time to neurological recovery of 10.75 months. Recurrence was seen in only one patient and was treated successfully by further surgery. Our results are similar to those reported by other authors. A successful surgical outcome depends on early diagnosis before neurological damage has occurred.